Gel intermediate



Patented June 9, 1942 TNT by mesne assignments, to William Yonkers, N.Y., as trustee H. Anderson,

No Drawing. Application December 20, 1938, s gai No. 240,901. In CanadaDecember 28,

Claims.

In the manufacture of chrome tanned leather and also in the employmentor utilization of such leather in the industries there is produced andrealized a considerable quantity of small pieces which may be referredto as scrap. Much of this scrap is in the form of shavings. 1

One object of this invention is to find a use fo this otherwiserelatively valueless material and to convert by chemical processescertain constituents of and derivable from the leather into valuableproducts useful in diverse commercial fields.

According to this invention the chrome tanned leather which is toprovide the base material from the process, be it scrap in the form ofcut pieces or scrap in the form of thin shavings, is preliminarilytreated with a solution composed of or comprising an aqueous solution ofhydrogen peroxide (H202) and soda ash (NaaCOa).

The preliminary treatment may be referred toas an alkalizing andbleaching step and by it there is effected a considerable bleaching ofthe leather being treated.

The preliminary bleaching step requires only a relatively short periodof time and during this period there is a color conversion from a lightgreenish tinge to a light yellow or amber color. Some of this change ofcolor may follow the oxidizing efiect of the hydrogen peroxide and someof the change of color may be due to the chemical reaction moreparticularly as between the metallic constituents in the leather, viz.,the chromium constituents on the one hand and the sodium constituents ofthe treating solution on the other hand.

The preliminary alkalizing and bleaching step is shortly followed or inefiect continued by the adding of a certain quantity of water to theleather-chemical solution mixture and by the stirring of the waterdiluted mixture whereby uniform conditions are established andmaintained throughout the mixture.

The water diluted mixture is continued for a relatively short but for asufficient period of time during which there is realized a furtherbleaching of the leather within the mixture and also a (or. 106-136) KBy the operations or steps referred to above. there is also realized areleasing, yielding or elimination from the leather being treated ofmuch but not all of the chrome content and of any other metallic contentthat may have been present in the leather undergoing treatment.

To the bleached leather base as a body while still containing asubstantial quantity of liquid substantial softening or plumping of theleather.

At the end of the bleaching period just mentioned there is anelimination of much of the solution from the mixture as by a strainingor draining operation.

In due time after the draining operation the leather is subjected torepeated washings, until the wash water is clear and colorless, and fromthis there results the washed leather which is herein referred to as thebleached leather base.

content carried thereby or entrained therein or therewith, there is nextadded and dispersed therethrough a'quantity of sulfuric acid, to wit, inamount preferably to result in an ultimate neutral product or mixturehaving a pH value of 7 without any marked tendency toward either thealkaline or acid side.

The mixture of the bleached leather base and sulfuric acid iscontinuously stirred and individually heated with a steam heated kettleor other suitable receptacle to a maintained temperature rangeapproaching but not quite reaching the boiling point of water at normalatmospheric pressures. This hot acid treatment is over quite an extendedperiod of time as compared with the preliminary alkalizing and bleachingoperations and is primarily carried out for the purpose of freeing andreleasing the gelatinous matter from the leather base material.

The hot acid treatment may also effect a slight amount of bleaching ifthe previous bleachings had not completed the bleaching.

It will here be remarked that the past history of the chrome tannedleather is such that the gelatinous product thus derived, and which maybe viewed as an animal protein product, is not contaminated with anysubstantial quantity of oils, fats, glycerine, orglycerides since suchor the basis therefor do not exist in any substantial quantity in theleather base being treated.

Applicant is of the opinion and view that the hot acid'treatment resultsin converting the metallic content remaining in the bleached leatherbase into the form of a soluble double salt that is dispersed throughoutthe dissolved or liquid gelatin, viz., specifically in the form of adouble sulfate'of sodium and chromium.

In this same general connection the inventor hereof ventures thesuggestion and in fact believes that the metallic content within thechrome tanned leather shavingsand more specifically the chrome contentthereof is converted by the alkalizing and bleaching steps into a formwhich is or which approaches sodium bichromate NazCrzOmZHzO and which bythe hot sulfuric acid treatment is converted into a liquid form which isor which approaches a sodium chromium sulfate represented by thechemical Cr2(SO4) 3.N8.2SO4.24H20.

Reverting now to the hot acid treatment, it is to be noted that this ispreferably continued until much of the water, but not all of it, hasbeen driven off.

The product at the end of the hot acid treatment still has therein acertain solids content that remains or continues as a solid residuewhich will not go into solution by the treatment mentioned and thissolid remainder has to be sep arated from the liquid gelatinous materialor portion by centrifugalizing or by filtering. The gelatinous materialthus obtained contains a substantial quantity of the double saltsdispersed throughout the same and from henceforth on they continue toconstitute a part of the ultimate product.

After the separation or elimination of the solids residue from the restof the liquid products as by centrifugalizing or filtering thegelatinous metallic salt product may be subjected to further treatment,as, for example, to further heating in order to, further dehydrate or tocomplete dehydration thereof.

A complete dehydration of the gelatinous metallic salt product wouldresult in a solid mass unless a cutting or diluting agent were appliedor added in order to maintain a liquid condition before the fulldehydration had been completed. A cutting agent suitable for suchpurpose is typifled by acetone, methyl acetone; methyl alcohol or theequivalent thereof and the quantity of such cutting agent which would beemployed at this juncture would be dependent upon the degree ofviscosity desired for the products produced by the steps and operationsabove outlined.

The product or products produced as above described is frequentlyreferred to herein as a gel intermediate because it is in fact anintermediate form of product that yields and leads to any one of severaltypes of ultimate use therefor and this statement applies regardless asto whether the intermediate product is in a solid form resulting fromcomplete dehydration or whether the liquid or viscous characteristicshave been retained, maintained, or acquired by or because of the used adiluting or cutting agent of the type mentioned.

formula When a gel intermediate is made as outlined it is relativelyclear, transparent, colorless, has a relativel high viscosity or can becaused to exist as a solid transparent mass much resembling glass in.appearance.

The gel intermediate produced by the invention hereof tends with propertreatment or manipulative operations to the receiving and embodimenttherein of coloring, solid filling, plasticizing or other fixing orconditioning material.

It readily receives and accepts plasticizing materials such asdiethylene glycol and triethanolamine. With proper manipulativeprecautions being taken it will receive and accept formaldehyde whichcan be employed and relied upon to serve as a gelatin fixing agent andto impart waterproofing and non-inflammable characteristics to theultimate product.

When the dissolving or cutting agents have been evaporated, as by airdrying or otherwise, so as to leave the resulting solid product justreferred to it will be found to have properties rendering it a goodelectrical insulating material, as well as being non-inflammable.

If in solid form, the gel intermediate can be dissolved by acetone orchemically-equivalent cutting agent and likewise as already indicated ifin a too heavy or high viscous form, it can be readily thinned by suchagents.

It will therefore be noted and appreciated that from the gelintermediate and with the following of appropriate treatment one canproduce mouldable plastics, solids in any suitable form such as blocks,sheets, films, viscous or liquid solutions applied as by painting,spraying, dipping, pouring, or otherwise and functioning so that whendried and solidified after application, the applied material can serveas a decorative, protecting, fireproofing, Waterproofing or electricalinsulating coating or means,

It will also be apparent from the specification hereof that the severalproducts can be made transparent so as to resemble ordinary windowglass, can be made transparent but so as tohave tinted or coloredappearance, can be made with solids dispersed therethrough as fillingmaterial, can be made with plasticizer embodied thus to impart flexibleand yielding qualities in order to avoid or resist cracking ordisrupting incident to flexing or use. If desired products derived fromthe gel intermediate may be employed due to sticky filamentaceouscharacteristics thereof as a binding or cementing agent, or even for theproduction of threads or filaments serving as fibers for use in thetextile industry.

The gelatinous intermediate product or gel intermediate as derived isrelatively free of oils, fats, glycerine and glycerides because of thepast history of the chrome leather base material and therefore are notencountered in the ultimate product as objectionable factors therein.

The gelatinous intermediate product essentially embodies therein thedouble salts result- .ing from the process and it is believed that suchsalts exist as uncrystallized sodium chromium sulfate uniformlydispersed within and throughout the gel,

Important objects and aspects of this invention therefore relate to andrevolve about the several intermediate, usable and ultimate productsproduced from the chrome tanned leather pieces or shavings as the basematerial.

The invention will now be referred to more in detail,

A specific mode of producing the gel intermediate First create anintimate mixture of (a) chromium leather waste lbs.)such as leathershavings or relatively fine cuttings(b) soda ash NazCOa as an alkalizingagent, 32 lbs. dry form and hydrogen peroxide H202 as an oxidizing andbleaching agent, 70 lbs. liquid form of the 3% technical solution. Inthis connection one would not ordinarily use the concentrated 30%technical solution.

The chrome leather at the start of the process has a greenish tintlightgreenish. As soon as the soda ash and the hydrogen peroxide start toreact in the presence of the leather, there follows a gradual change inthe color characteristics of the leather toward a light yellow or amber.During the treating of the leather by the chemicals in the mixture thereis a constant stirring in order to attain and maintain an intimatemixture in which the leather particles or shavings are thoroughlydispersed throughout the liquid of the mixture. This stirring is for aperiod of approximately 5 minutes, or as otherwise expressed, until theleather (all of the leather in the mixture) is properly converted. intothe form desired, that is, until all of the leather has taken theuniform and developed light color and the liquid has taken on adecidedly light yellow or amber color. Another purpose of this early orpreliminary operation is to eliminate, yield or release -a largeproportion of the chrome constituents (be it in the-form of a salt orotherwise) from the leather or any other metallic constituents residingor embodied in the leather after the tanning. This preliminaryalkalizing and bleaching operation does not remove all of the metallicconstituents.

Chrome leather shavings with which this invention or the process of thisinvention starts has at the outset at the most only a very small amountof fat and hence immediately following the steps already described?there is added to the material constituting the batch or mixture arelatively limited quantity of water, for example, approximately 64 lbs.of water and there is further carried out a continued stirring of thebatch for about ten minutes more and thereafter the liquid content isquite considerably eliminated as by straining, draining or othermanipulative dewatering operation. .'The continued operation of stirringthe, added water into the batch prior to the dewatering operation justreferred to serves to continue or further and to make more uniform theleather bleaching operation and this statement applies even though thebleaching liquid has been much diluted by the added water. The addedwater aids in softening or plumping the leather. The diluted solutionadditionally serves in the washing off and removing of metallic solidsfrom the treated leather shavings. As a matter of fact during theoperations above described, there. is a sampling of the batch byremoving and testing portions thereof to see if the initial bleaching orcolor conditioning treatment has been carried to the desired point andlikewise after the adding of the water there is a sampling of shavingsfrom the batch to determine as to whether the bleaching ultimatelydesired for this step has been attained.

Now bearing in mind that much of the liquid from the continued bleachingoperation has been eliminated, it is to be noted that further andrepeated washings of the solids of the batch are carried out by suppliesof clear or relatively pure water until there is no substantialdiscoloration of the wash water as it leaves the batch. If aparticularly white product is desired there may be added a solution ofsulfuric acid 66 Baume. For example, about 1 lb. of such solution isadded to the last batch or lot of wash water. It will also be noted thatat the end of this washing chromium in the form of an oxide or sodiumcompound is still present in a substantial amount, for example, in anamount approximately up to 0.2% m the leather shavings which have thusfar been treated.

The foregoing may be viewed as the preparation steps applied to thebasic leather material,

to wit, to the chrome leather shavings and the 6 resulting product fromthe preparation or pretreatment operations just described will bereferred to as the pre-treated chrome leather base material, or asotherwise expressed, as the washed bleached leather base, or even as thebleached leather base.- v

The body of the pre-treated chrome leather basematerial which has beenwashed and from which much of the wash water has been eliminated bydraining, decanting or otherwise still holds a certain quantity of waterembodied there: in and entrained therewith even after the decanting orstraining operations and it is promptly placed in a steam-jacketedkettle provided with a mechanical agitating means functioning thereinand thereto there are added 42 lbs. of a 10% solution of commercialsulfuric acid, to wit, 66 name. The liquid-solids content nowconstituting the charge or batch within the kettle is maintained'attemperatureswithln an approximate range of between to F., thetemperature of the charge or batch should never rise to the boilingpoint viz., to 212 F. Material constituting'this batch or charge isheated for a period of approximately between 1 hour and 1 hour and ahalf and is continuously stirred in a manner to avoid. hardening on thesides of the kettle. If the heating and stirring were carried out insideof a vacuum kettle, or a'kettle wherein the vapor pressures weremaintained substantially below atmospheric pressure, then thetemperature ranges for heating can be correspondingly reduced.

The sulfuric acid and heating treatment just referred to is for the dualpurpose of extracting, releasing or yielding the gelatinous matter fromthe bleached leather base and also for evaporattiiggtofl a substantialquantity of the water con- The amount of sulfuricacid used for a batchof the size stated is as previously indicated about 42 lbs. of the 10%commercial sulfuric acid, or an adjusted amount of sulfuric acid if anacid of diiferent strength is used. As a matter of fact other acidsmight be employed for extracting the gelatinous matter, for example,such as acetic acid or lactic acid but in general the sul- As-a measureor in-,

furic acid is preferable. dication of the quantity of acid, that shouldbe supplied to the kettle charge, one should bear in mind that theultimate product should be neutral, viz., have a pH value of 7.

This acid treatment is followed .by a relatively quick separating of theliquid of the batch from the solid residues that may exist therein, thisseparating is carried out preferably while the batch is still hot,either by a centrifugal operation or by a filtering operation. Theproduct sought from this treatment is a relatively clear one having ahigh viscosity; when warm it may be described as in the form of arelatively light gel of low viscosity and when cold it may be describedasa relatively heavy gel of high viscosity. It still contains asubstantial quantity of metallic content mostly, it not entirely, in theform of a double salt, to wit, in the form of a sodium chromium sulfate.

For 'the purpose of having a name which can be employed as a typifyingname for the prodnot just mentioned, be it warm in a light gel form, orcold in a heavy gel form, or even in a solid form, it may be and hereinis referred to as a gel intermediate.

This intermediate as has been previously indi-' cated is used as afoundation material from which any one of several'more specific forms of70 products can be produced by appropriate processes that may be.employed.\ From the gel intermediate one is enabled to produce as hasheretofore been pointed out many ultimate products for sale over thecounter, or for use in other industries, to wit, products ranging fromand tions to other products in order to provide a fireproofing, anelectrical insulating, or a waterproof coating or the like, whichsolutions may be applied as by spraying, brushing, or dippingoperations. I

Liquid products or solutions having low viscosity may be produced fromthe gel intermediate by takinga quantity of the gel intermediateproduced as above outlined and thinning it or cutting it by mixingtherewith a diluting or cutting agent such as acetone or methyl acetoneor methyl alcohol, or the equivalent thereof.

Examples as to mode of employing or adapting the gel intermediate forcertain specific products As typifying a liquid product or solutionhaving a low viscosity, reference is made to one embodying 70% by weightof the gel intermediateand 30% by weight of acetone orchemicallyequivalent diluting or cutting agent. This solution is warmedto a temperature of about 135? F. and when at the approximatetemperature just mentioned there is added 3% of di-ethyleneglycol whichis stirred or mixed by agitation into and throughout the solution.Thereafter the solution is cooled to a 90 F. To the cooled solutionabout one-half of 1% of formaldehyde (40% solution) is slowly added orintroduced as by spraying and is thoroughly dispersed within andthroughout the solution. It will be remarked that if the introduction ofthe formaldehyde is not slow, in small quantities and gradual thatinsoluble lumps will be formed which would have to be separated out asby straining. The di-ethyleneglycol is served as a plasticizer; theformaldehyde functions to insure the waterproofing and non-inflammablecharacteristics. If a colored product or if what is known in the tradeas a filled or weighted product is desired then suitable materials couldnow be added and dispersed throughout the solution for accomplishingthat purpose. Such a solution as that just described will shortly afterits application to the object with which it is used and upon air dryingor other evaporating operation result in a solid coating because thediluent solvents therein are of a character whereby they readilyevaporate. The time for this drying in air is approximately one-halfhour.

When the gel intermediate is to be converted into a liquid product orsolution having high viscosity for use, for example, as a binder in themanufacture of safety glass or even for wide sheet or narrow stripmaterial, then a quantity of the gel intermediate has mixed therewith asolvent in the form of a diluting or cutting agent such as has beenmentioned herein. For example, a typical solution having high viscosityis one made up of or comprising 95% of gel intermediate andapproximately 5% of, the methyl or cutting agents could serve thispurpose. This mixture is warmed to approximately 135 F., and issimultaneously stirred for about five minutes so that the resultingsolution is relatively uniform throughout and while still warm there isadded about 4% of triethanolamine. The solution is stirred while thelast mentioned chemical is being added and this operation takes abouttwo minutes. Thereafter the solution is cooled to about F., and there isadded about onehalf of 1% of formaldehyde (40% solution). The

triethanolamine is added as a plasticizer where a particularly clear andtransparent sheet is desired.

Where the gel intermediate is employed to produce a product to be usedas mouldable plastic then there may be required primarily only theaddition of coloring or filling material and this may be introduced bykneading the same into a mass of the gel intermediate while the latteris warm. If it is desired to facilitate the flowing and to further themoulding characteristics of the ultimate product to be used as amouldable plastic, it may be advisable to introduce a quantity ofplasticizer into the batch before the introduction of the loading orcoloring material and in 'some instances it may be still furtheradvisable to introduce a diluting or cutting'agent even beforeintroducing the plasticizer by performing steps in a manner the same oranalogous to those heretofore described.

Where the gel intermediate is employed to make lacquers especially andparticularly useful for coating the surfaces of wood or metallicobjects, it may be advisable to impart more lustre and heavier bodycharacteristics than would otherwise be the case and to that end theremay be employed gum dammar or copal.

To produce such a lacquer the gel intermediate is preferably thinned bythe addition of any one of the diluting or cutting agents mentioned as,for example, methyl acetone. This addition is made while the mixture orsolution is warm and while it is being agitated. While the mixture isstill warm preferably at the approximate temperature of F., the desiredamount of plasticizer is introduced as, for example, eitherdiethyleneglycol or triethanolamine, and there is also added a quantityof gum dammar or copal. The amount of the latter to be added variesconsiderably-according to the particular characteristics and usedesired. The resulting mixture may be composed of 70% of the plasticizedgel intermediate, and 30% of a solution containing the gum dammar orcopal dissolved in acetone, methyl acetone or other alcoholicderivative. The gum dammar or copal solution just referred to may be onemade up, for example, from a pound of gum dammar dissolved in a pound ofacetone or the like but in this connection it will be noted that aconsiderable variation in proportions can be resorted to and the desiredresults can be readily obtained.

A lacquer made from the gel intermediate has been actually applied bydipping a fabric covered electric cable into a bath of the lacquer andshortly after air drying such cable well withstood the heat from theflame of a Bunson burner applied directly thereto.

The inventor realizes and believes that he has discovered and invented(a) a process involving a novel series of chemical steps and operationsfor obtaining from chrome tanned leather waste a gel intermediate or gelintermediates of broad and general application; (b) a gel intermediatewhich is, or gel intermediates which are new and novel; and employmentof such novel gelintermediate or intermediates, resulting in novel anduseful products and while he intends to claim as his invention suchnovel process, intermediate products, and novel ultimate usableproducts, nevertheless, he believes he has invented or discovered a morefundamental and far-reaching subject matter of patentable invention orimprovement than that involving the mere treating of chrome leatherwaste and the products derivable therefrom.

Applicant believes he is the first to produce from suitablegelatine-yielding or gelatin-providing stock or base material, a gelintermediate that is substantially free of contaminating constituentssuch as fats and oils but which contains and embodies intimatelycombined a substantially fat-free or substantially oil-free gelatin baseor starting material and a double salt of chromium typified andidentified as a double sulfate of sodium and chromium. Applicantbelieves he is the first to make and to use such a novel gelintermediate in the production of ultimate products as herein describedand he hereby sets forth and declares his intention to claim broadlysuch novel gel and also its broad, as well proximately to 50 pounds, butso as to leave- 10 therein a small water content which may be, by

aasaoas as its-specific uses, as herein outlined or indicated.

The invention possesses other objects and features of advantage, some ofwhich have been set forth and enumerated in the description and some ofwhich are further indicated by the claims hereof. In the description andin the claims, parts are identified by specific names for convenience.In this specification there have been described certain of the bestembodiments of and the modes for realizing the invention known to me,but such disclosure is to be regarded as typical only of and indicativeof many other possible modes or realizations of the invention and theinvention is not to be limited by the specific disclosure hereof.

The novel features considered characteristic of my invention are setforth with particularity in the appended claims. The invention itself,however,'both as to its manner of realization and its method ofoperation, together with additional objects and advantages thereof, willbest be understood from the description herein of the specificdisclosure when read in connection with the amplifying statementappearing in this specification.

The gel intermediates can be diluted or out and the solid ultimateproducts realized from drying the viscous gel products can be partiallydissolved or completely dissolved by employing the cutting and dilutingagentsmentioned. Sheeted material made from the intermediates can besoftened by applying suitable cutting or diluting until they are insolution and until a with and in general should be manifest from thatwhich has preceded.

Where one desires to produce a particular high grade grease-proofproduct then this may be realized as follows:

First step-Take 100' pounds of the gel intermediate produced as alreadydescribed and which has been evaporated to one half its weight,-ap-

way of example, of approximately from 5 to 8%. Second step-Take 5 poundsof vinylite resin A having viscosity 15 to which there has been added 2pounds of concentrated acid (not acetic anhydride) whereby the weight ofthe resulting mixture of the resin and the added acid is approximately 7pounds. The adding of concentrated acid to the vinylite A must beaccompanied by constant stirring until there is obtained an emulsion.

Third step-Take 5 pounds of acetone. and add this to the'acetic mixtureof the second step. The acetone which is added to the emulsified mixturefrom the second step is constantly stirred into the emulsion, that is tosay into the mixture of vinylite A and the concentrated acetic acid,sample placed on a glass plate showsv clear.

Fourth step-The mixture of vinylite A and concentrated acetic acid andacetone, namely, from the third step is addedslowly to the gelintermediate of the first step. This addition must be slow and must beaccompanied with very rapid stirring so as to insure no separation orlumps in the final product.

When the steps are carried out as above outlined there is realizable asolution sufiiciently viscous to be applied as a coating agent to asheet, fabric, carton or the like. The vinylite resin A functions inthis mixture to serve as-a spreading agent filling any pores that mightotherwise tend to form. This mixture or resulting liquid or viscousproduct responds readily to quick drying and evaporation. A coating madetherefrom is both grease-proof and water-proof and is sufiicientlyflexible to entirely or substantially eliminate cracking of the coatingin ordinary use.

Thinning agents, plasticizing agents and the like may be used to meetthe required results.

agent and this characteristic can be employed that they will not readilyfracture. The resulting ultimate products will not splinter and they arenon-odorous, non-toxic and strong.

The foregoing observations are in harmony What is claimed is:

1. The method of producing agel intermediate of' the class describedincluding employing chrome tanned leather as a base material relativelyfree of oil and fat impurities, subjecting such base material to thereactive eifects of an aqueous alkalizing and bleaching solutionessentially comprising an alkaline sodium compound and an oxidizingagent, removing a quantity of the solution from the solid material aftera substantial bleach has been realized therefor, thereafter washing thesolid material with water and removing a substantial quantity of theliquid from the washed solid material, introducing a quantity ofsulfuric acid into the partially dewatered washed solid material andsubjecting the same to a heat treatment within an approximatetemperature range of to F. for a period. of time of approximately 1 hourto 1 /2 hours duration, thereafter removing solids constitutingimpurities from the resulting liquid-.

form product, which resulting product still contains water therein, andultimately eliminating the water content and'incorporating a dilutingand cutting agent whereby the product thereby obtained is a viscoussolution adapted for various modes of employment.

2. In the production of a gel intermediate as described herein, theprocess comprising treating of chrome tanned leather scraps by a processincluding subjecting the leather scraps to an aqueous alkalizing andbleaching solution essentially comprising an alkaline sodium compoundand an oxidizing agent, removing a quantity of the bleaching solutionfrom the mass of bleached solid material, washing the bleached mass,ex-' posing the washed bleached mass to an aqueous solution of sulfuricacid while heating and agitating the same under conditions favorable tothe release and derivation of gelatinous matter from the bleached basematerialwhereby the gelatinous matter which is in liquid phase can bereadily separated from the residue matter in solid phase. separating thematter in solid phase and the gelatinous matter in liquid phase, heatingthe thus obtained gelatinous matter in liquid phase so as to eliminate asubstantial quantity of the water content thereof and also adding anddispersing throughout the hot solution a liquid cutting and dilutingagent, and ultimately eliminating the remainder of the water content butunder conditions whereby the resulting gel intermediate is in the formof a viscous fluid because of the continued existence therein of atleast a substantial quantity of the cutting and diluting agent.

3. The utilization of a gel intermediate produced as defined in and bythe claim last preceding and according to which another employableproduct is produced from the gel intermediate by intimately dispersing aplasticizing agent while the gel intermediate is at a temperature ofapproximately 135 F.

4. The utilization of a gel intermediate produced as defined in and byclaim 2 and according to which another employable product is produced bydispersing a plasticizing agent within and throughout the gelintermediate while the latter is at temperatures approximating 135? F.,by cooling the resulting solution to approximately 90 F., and bygradually adding a gelatin-fixing and waterproofing agent to the cooledsolution while stirring the same.

5. A product which is substantially identical with the product made fromchrome tanned leather waste as a base material therefor by a processincluding initially alkalizing, bleaching and plumping the base materialby subjecting it to the action of soda ash and hydrogen peroxide in anaqueous solution, eliminating a substantial quantity of the liquidcontent of the mixture and thereafter subjecting the bleached basematerial to repeated washings, eliminating from the washed bleached basematerial a quantity but not all of the liquid content, thereafter addingand ultimately dispersing sulfuric acid to and throughout the washedbleached base material and heating the resulting menstruum thus formedto within a temperature range of 'approximately between 190 to 195 F.,and continuously stirring the same and until the gelatinous matter andresulting sodium chromium sulfate are yielded in liquid form permittingthe separation thereof from the residual solid portions of the leather,thereafter separating the liquid matter from the solid residue forthereby obtaining a product essentially comprising a gelatinous materialwith a sodium chromium sulfate salt dispersed therein.

6. A method as defined in and by claim 1 and in which there aresuccessive applications of wash water to the bleached mass of solidmaterial and in which a quantity of sulfuric acid is added to the washwater employed immediately the hot sulfm'ic acid treatment.

'7. A product which is substantially identical with the product producedby steps essentially comprising subjecting a mass of chrome tannedleather as a gelatin-yielding base material that is substantially oiland fat free and having a chromate containing radical therein to anaqueous alkalizing and bleaching treatment by ahead of intimately mixingwith and throughout the same a solution essentially comprising analkaline sodium compound and an oxidizing agent, thereafter removing asubstantial quantity of the liquid content of the mass, washing withwater the thus bleached solids content of the mass,

removing liquid content from the mass and thereby leaving the solidscontent. of the mass with a relatively small quantity of liquid contentdispersed throughout the same, thereafter mixing with the washed solidsof the mass aqueous sulfuric acid in quantities suillcient to furtherthe release and derivation of gelatinous matter from the mass ofbleached solids, heating and simulof chrome tanned leather as a basematerial rela- 7 tively free of oil and fat impurities, subjecting suchbase material to the reactive eflfects of an aqueous alkalizing solutionessentially comprising an alkaline sodium compound, removing a quantityof the solution from the mass of solid material after a substantialalkalizing reaction has been realized therefor, thereafter washing thealkalized mass of'base material with water and removing a substantialquantity of the liquid from thewashed mass, introducing a quantity ofsulfuric acid into the partial dewatered washed mass and subjecting thesame to a heat treatment within an approximated temperature range of 190to 195 F. fora period of time of approximately 1 hour to 1 hoursduration, thereafter removing solids constituting impurities from theresulting liquid-form product, which resulting product still containswater therein, and ultimately eliminating the water content andincorporating a diluting and cutting agent whereby the product therebyobtained is a viscous solution adapted forvarlous modes of ultimateemployment.

9. -A product for use in diverse manners and substantially identicalwith the product produced from chrome tanned leather waste as a basematerial therefor by a process including initially alkalizing andplumping such waste base material by subjecting it to the action of sodaash in an aqueous solution, eliminating a substantial quantity of theliquid content of the mixture and thereafter subjecting the plumpedleather waste to repeated washings, eliminating from the washed plumpedwaste a quantity but not all of the liquid content, thereafter addingand ultimately dispersing sulfuric acid to and throughout the washedplumped leather waste and heating ing the liquid matter from the solidresidue fort thereby obtaining a gel intermediate essentially comprisinga gelatinous material with sodium sulfate salt dispersed therein.

10. A product which is substantially identical with the product producedby steps comprising subjecting chrome tanned leather as agelatinyielding base material that is substantially oil and fat free andhaving a chromate containing radical therein to an aqueous alkalizingand bleaching treatment by intermittently mixing with and throughoutsaid base material a solution essentially comprising an alkaline sodiumcompound and an oxidizing agent, thereafter removing a substantialquantity of the liquid content of the resulting mass of alkalined andbleached base material, washing with water the thus bleached solidscontents of the mass, removing liquid content from the washed mass andthereby leaving the solids content 01 the mass with a relatively smallquantity of liquid dispersed throughout the same, thereafter mixing withthe solids oi the thus dewatered mass aqueous sulfuric acid inquantities sumclent to further the release and derivation of gelatinousmatter from the mass of bleached solids, heating and simultaneouslyagitating the mass to which the sulphuric acid has been added until thegelatin-yielding material of the mass has been converted into liquidphase, thereafter separating the remaining residue as impurities fromthe resulting liquid phase product whereby the latter is obtained as arelatively clear liquid phase product but in which there is included acertain quantity of water content, and further k treating and processingsuch clear liquid phase product soas to eliminate the water content andincorporating a diluting and cutting agent whereby the resulting productis in the form of a de-, hydrating viscous solution adapted -for variousmodes of ultimate employment. I

WILLE'I'I'. C. PERSON.

